Ricoh Reveals GR IV HDF With Built-In Highlight Diffusion Filter
Japanese company Ricoh has announced the upcoming release of the GR IV HDF, a new variant of its GR IV premium compact camera that replaces the built-in neutral density filter with a Highlight Diffusion Filter.
The GR IV HDF shares the same core platform as the standard GR IV, including a 25.7-megapixel APS-C CMOS sensor, a fixed 18.3mm f/2.8 lens (28mm equivalent), and Ricoh’s latest image processor. The main distinction lies in the integrated Highlight Diffusion Filter, which can be activated or deactivated via a dedicated control. When enabled, the filter softens highlight areas and bright light sources, producing a diffused rendering that reduces edge contrast while leaving non-highlight areas largely intact. When disabled, image output matches that of the standard GR IV.
Ricoh first introduced the HDF concept with the GR III HDF and GR IIIx HDF in 2024. The filter is based on inkjet-derived microstructure technology and is positioned near the lens aperture. Its extremely thin construction allows it to be moved in and out of the optical path using a small motor, without requiring changes to the lens or body design. Unlike a traditional diffusion filter placed in front of the lens, the effect is controlled internally and can be applied selectively on a shot-by-shot basis.
Because the HDF replaces the ND filter found in the standard GR IV, Ricoh has added a high-speed electronic shutter to compensate. The GR IV HDF supports shutter speeds up to 1/16,000s, compared to the 1/4,000s limit of the mechanical shutter, thus allowing the camera to maintain wide apertures in bright conditions despite the absence of an ND filter. Ricoh has confirmed that this electronic shutter capability will later be added to the standard GR IV via firmware.
Externally, the GR IV HDF is nearly identical to the base model, with the most visible difference being a silver-colored shutter release button. The function button is also assigned to HDF control by default, rather than AF/AE lock. Other specifications remain unchanged, including 5-axis sensor-shift image stabilization rated up to six stops, hybrid autofocus with subject detection, ISO sensitivity from 100 to 204,800, 53GB of internal storage, and a 3-inch rear LCD with touch support.
The Ricoh GR IV HDF will be displayed at Ricoh GR Space retail locations starting December 17 and is scheduled to begin shipping in late January. It will be priced at $1,599.95, positioning it $100 above the standard GR IV, which is already on sale.
Alongside the HDF model, Ricoh has confirmed development of a GR IV Monochrome. This version will use a monochrome APS-C sensor without a color filter array, allowing it to capture black-and-white images only. Ricoh states that it will include image control modes tailored specifically for monochrome photography. The GR IV Monochrome is currently scheduled for release in spring 2026, with pricing yet to be announced
